biological science vs persistent

biological science is a noun but persistent is not a noun.

Word	Noun	Adjective	Verb	Adverb
biological science	Yes	No	No	No
persistent	No	Yes	No	No

biological science (noun)	persistent (noun)
the science that studies living organisms

biological science (adjective)	persistent (adjective)
	retained; not shed
	never-ceasing
	stubbornly unyielding
	continually recurring to the mind